Now Moses’ father-in-law Jethro, the priest of Midian, heard about all that God had done for Moses and His people Israel, and how the LORD had brought Israel out of Egypt.
1. When Jethro, the priest of Midian. This chapter consists of two parts. First of all, the arrival of Jethro in the camp is related, and his congratulation of Moses on account of the prosperity of his enterprise, together with the praise and sacrifice rendered to God.
This incident may very well be allowed to have happened as it is placed here, before the giving of the law, and not, as some place it, in connection with what is recorded, Num 10:11, Num 10:29, etc. Sacrifices were offered before; in these mentioned here (Exo 18:12) it is observable that Jethro is said to take them, not Aaron.
Commenting on Exodus 18:1-6
When Jethro the priest of Midian, Moses's father-in-law,.... The Targums of Onkelos and Jonathan call him the prince of Midian, and so the word (e) is rendered in some versions; whose daughter Moses had married, and so was his father-in-law, of which see more in Exo 2:16.